From d6d01cd278f00f68d162990e7fa793de08a39b6a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matu=CC=81s=CC=8C=20Tomlein?= <matus.tomlein@gmail.com>
Date: Mon, 10 Jul 2023 15:56:39 +0200
Subject: [PATCH] Add processUserId callback to transform the userId such as
 for hashing

---
 .../browser-plugin-focalmeter/src/index.ts    | 15 ++++++-----
 .../test/request.test.ts                      | 25 ++++++++++++++-----
 2 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/plugins/browser-plugin-focalmeter/src/index.ts b/plugins/browser-plugin-focalmeter/src/index.ts
index ee77fd133..ef2c290f8 100644
--- a/plugins/browser-plugin-focalmeter/src/index.ts
+++ b/plugins/browser-plugin-focalmeter/src/index.ts
@@ -43,6 +43,8 @@ export interface FocalMeterConfiguration {
   kantarEndpoint: string;
   /** Whether to store information about the last submitted user ID in local storage to prevent sending it again on next load (defaults not to use local storage) */
   useLocalStorage?: boolean;
+  /** Callback to process user ID before sending it in a request. This may be used to apply hashing to the value. */
+  processUserId?: (userId: string) => string;
 }
 
 const _trackers: Record<string, BrowserTracker> = {};
@@ -77,21 +79,22 @@ export function FocalMeterPlugin(): BrowserPlugin {
         return;
       }
 
-      let newUserId = payload['duid'] as string;
-      let { kantarEndpoint, useLocalStorage } = _configurations[trackerId];
+      const newUserId = payload['duid'] as string;
+      const { kantarEndpoint, useLocalStorage, processUserId } = _configurations[trackerId];
 
       if (!lastUserId && useLocalStorage && hasLocalStorage()) {
-        let key = getLocalStorageKey(trackerId);
+        const key = getLocalStorageKey(trackerId);
         lastUserId = attemptGetLocalStorage(key);
       }
 
       if (newUserId && newUserId != lastUserId) {
         lastUserId = newUserId;
+        const processedUserId = processUserId !== undefined ?  processUserId(newUserId) : newUserId;
 
-        sendRequest(kantarEndpoint, newUserId, LOG, () => {
+        sendRequest(kantarEndpoint, processedUserId, LOG, () => {
           // only write in local storage if the request succeeded
           if (useLocalStorage && hasLocalStorage()) {
-            let key = getLocalStorageKey(trackerId);
+            const key = getLocalStorageKey(trackerId);
             attemptWriteLocalStorage(key, newUserId);
           }
         });
@@ -141,7 +144,7 @@ function sendRequest(url: string, userId: string, LOG: Logger, successCallback:
 }
 
 function getKantarURL(url: string, userId: string): string {
-  let query: Record<string, string> = {
+  const query: Record<string, string> = {
     vendor: 'snowplow',
     cs_fpid: userId,
     c12: 'not_set',
diff --git a/plugins/browser-plugin-focalmeter/test/request.test.ts b/plugins/browser-plugin-focalmeter/test/request.test.ts
index 0b62a978a..40ec88ecd 100644
--- a/plugins/browser-plugin-focalmeter/test/request.test.ts
+++ b/plugins/browser-plugin-focalmeter/test/request.test.ts
@@ -60,11 +60,11 @@ describe('AdTrackingPlugin', () => {
   });
 
   it('makes a request to Kantar endpoint with user ID', async () => {
-    let tracker = createTrackerWithPlugin();
+    const tracker = createTrackerWithPlugin();
     enableFocalMeterIntegration({ kantarEndpoint: domain });
 
     tracker?.trackPageView();
-    let userId = tracker?.getDomainUserId();
+    const userId = tracker?.getDomainUserId();
 
     await checkMock(() => {
       expect(xhrOpenMock).toHaveBeenCalledTimes(2);
@@ -72,8 +72,21 @@ describe('AdTrackingPlugin', () => {
     });
   });
 
+  it('makes a request to Kantar endpoint with processed user ID', async () => {
+    const tracker = createTrackerWithPlugin();
+    enableFocalMeterIntegration({ kantarEndpoint: domain, processUserId: (userId) => userId + '-processed' });
+
+    tracker?.trackPageView();
+    const userId = tracker?.getDomainUserId();
+
+    await checkMock(() => {
+      expect(xhrOpenMock).toHaveBeenCalledTimes(2);
+      expect(xhrOpenMock).toHaveBeenLastCalledWith('GET', `${domain}?vendor=snowplow&cs_fpid=${userId}-processed&c12=not_set`);
+    });
+  });
+
   it('makes a request to Kantar endpoint when user ID changes', async () => {
-    let tracker = createTrackerWithPlugin();
+    const tracker = createTrackerWithPlugin();
     enableFocalMeterIntegration({ kantarEndpoint: domain });
 
     // Doesn't make a request if anonymous tracking
@@ -86,7 +99,7 @@ describe('AdTrackingPlugin', () => {
     // Makes a request when disabling anonymous tracking
     tracker?.disableAnonymousTracking();
     tracker?.trackPageView();
-    let userId = tracker?.getDomainUserId();
+    const userId = tracker?.getDomainUserId();
     await checkMock(() => {
       expect(xhrOpenMock).toHaveBeenCalledTimes(2);
       expect(xhrOpenMock).toHaveBeenLastCalledWith('GET', `${domain}?vendor=snowplow&cs_fpid=${userId}&c12=not_set`);
@@ -100,8 +113,8 @@ describe('AdTrackingPlugin', () => {
   });
 
   it('can work with multiple trackers', async () => {
-    let tracker1 = createTrackerWithPlugin();
-    let tracker2 = createTrackerWithPlugin();
+    const tracker1 = createTrackerWithPlugin();
+    const tracker2 = createTrackerWithPlugin();
 
     enableFocalMeterIntegration(
       {